Apparatus and method for treating a neuromuscular defect

ABSTRACT

One aspect of the present disclosure relates to a treatment probe comprising an elongated body member and a needle portion. The elongated body member can have a proximal end portion and a distal end portion. The needle portion can be connected to the distal end portion. The needle portion can include at least one electrode and at least one fluid port. The at least one electrode and the at least one fluid port can be configured to deliver electrical energy and a tumescent fluid, respectively, so that superficial tissue planes overlying a target nerve are protected from inadvertent heat damage as a result of application of electrical energy to a target nerve.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/788,322, filed Mar. 7, 2013, now U.S. Pat. No. 9,204,925 which is acontinuation-in-part of U.S. patent application Ser. No. 12/541,221,filed Aug. 14, 2009, now U.S. Pat. No. 8,512,715, issued Aug. 20, 2013,which claims priority from U.S. Provisional Patent Application Ser. No.61/089,015, filed Aug. 14, 2008. The subject matter of each of theaforementioned applications is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present disclosure relates generally to an apparatus and method forneuromodulation, and more particularly to an apparatus and method forinterrupting nerve conduction through a target nerve to treat aneuromuscular defect.

BACKGROUND

The human nervous system senses current information and conditions,which it then sends to various muscles to respond. As one example,consider the facial and neck nerves. These motor nerves control themuscles of facial expression and, thus, an individual's outwardmanifestations of well being and emotion. Neuromuscular defects candisrupt this information exchange and lead to undesired muscleresponses.

The involuntary contraction of facial or neck muscles (also known asdystonias) can distort an individual's facial expressions and garble theoutward appearance of the individual's feeling of well being andemotional state. For example, one type of dystonia, calledblepharospasm, creates uncontrolled blinking and spasms in the eyelids.Another form of dystonia causes uncontrolled grimacing. Dystonias canalso affect neck muscles. For example, one form of dystonia, calledtorticollis, causes uncontrolled contraction of the neck muscles.

Apart from these hyperfunctional disorders, normal contraction of facialand neck muscles (e.g., by frowning or squinting) can form permanentfurrows or bands in the skin over time. These furrows or bands canpresent an aesthetically displeasing cosmetic appearance, and exposureto the sun can accelerate this undesired wrinkling process. As a morespecific example, the facial muscle corrugator supercilii draws theeyebrows downward and inward, producing vertical wrinkles of theforehead (also called glabellar frown lines). For this reason, thecorrugator supercilii is known as the frowning muscle and has beencalled the principal agent in the expression of suffering. Dystoniasaffecting the corrugator supercilii can lead to an unfortunate,continuous frowning expression, as well as the formation ofhyperfunctional frown lines and wrinkles in the face.

A surgical forehead lift procedure is one therapeutic modality oftenused to remove glabellar frown lines. The forehead lift requires a largeincision that extends from ear to ear over the top of the forehead. Thissurgically invasive procedure imposes the risk of bleeding and creates alarge skin flap that reduces blood supply to the skin. Numbness ofsensory nerves in the face, such as the supraorbital nerve can alsoresult.

A less invasive therapeutic modality is the administration ofinvertebrate exotoxins. For example, injection of the serotype A of theBotulinum toxin produces a flaccid paralysis of the corrugatorsupercilii. Tests have demonstrated that Botulinum toxin A may beadministered into the musculature of the face without toxic effect toproduce localized muscle relaxation for a period of about six months.The desired removal of hyperfunctional frowning lines is temporary, andrepeated treatments are needed about every 3 to 6 months.

Another form of treatment, disclosed in U.S. Pat. No. 5,370,642 toKeller, uses laser energy to eliminate glabellar frown lines andforehead wrinkles. The laser energy is used to resect large sections ofthe corrugator supercilii (as well as other facial muscles) and therebyinactivate the muscles. Like the surgical forehead lift, numbness of thesupraorbital nerve and other sensory nerves in the face can result.

SUMMARY

One aspect of the present disclosure relates to a treatment probecomprising an elongated body member and a needle portion. The elongatedbody member can have a proximal end portion and a distal end portion.The needle portion can be connected to the distal end portion. Theneedle portion can include at least one electrode and at least one fluidport. The at least one electrode and the at least one fluid port can beconfigured to deliver electrical energy and a tumescent fluid,respectively, so that superficial tissue planes overlying a target nerveare protected from inadvertent heat damage as a result of application ofelectrical energy to a target nerve.

Another aspect of the present disclosure relates to a method fortreating a neuromuscular defect in a subject. One step of the method cancomprise providing a treatment probe. The treatment probe can include abody member having a proximal end portion, a distal end portion, and aneedle portion connected to the distal end portion. The needle portioncan include at least one electrode and at least one fluid port that isoppositely disposed from the at least one electrode. Next, the needleportion can be positioned about a target nerve. A tumescent fluid canthen be injected into the tissue surrounding the target nerve via the atleast one fluid port. An electric current can be delivered to the atleast one electrode to substantially ablate the target nerve.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present disclosure will becomeapparent to those skilled in the art to which the present disclosurerelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view showing a treatment probe constructed inaccordance with one aspect of the present disclosure;

FIGS. 2A-B are magnified perspective views showing a needle portion ofthe treatment probe in FIG. 1;

FIG. 3A is a cross-sectional view taken along Line 3A-3A in FIG. 2A;

FIG. 3B is a cross-sectional view taken along Line 3B-3B in FIG. 2B;

FIG. 4 is a cross-sectional view showing an alternative configuration ofthe needle portion in FIG. 3A;

FIG. 5 is a cross-sectional view showing an alternative configuration ofthe needle portion in FIG. 3B;

FIG. 6 is a process flow diagram illustrating a method for treating aneuromuscular defect in a subject according to another aspect of thepresent disclosure;

FIG. 7 is a schematic illustration of a subject's orbital region showinguncontrolled blinking or blepharospasm;

FIG. 8 is an anterior view of the right side of the face showing thesuperficial facial and neck muscles and the branches of the facialnerves that control the facial and neck muscles;

FIG. 9 is a perspective view showing the distal end portion of thetreatment probe in FIG. 1 being positioned about a target nerve;

FIG. 10 is a perspective view showing the treatment probe in FIG. 9being used to deliver a tumescent fluid to the tissue surrounding thetarget nerve;

FIG. 11A is a perspective view showing a neuromuscular junction locatedbetween a target nerve and a muscle;

FIG. 11B is a perspective view showing the needle portion of thetreatment probe in FIG. 1 being used to substantially ablate the targetnerve; and

FIG. 12 is a schematic illustration showing the subject in FIG. 7 afterbeing treated for blepharospasm according to the present disclosure.

DETAILED DESCRIPTION

Definitions

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the present disclosure pertains.

In the context of the present disclosure, the singular forms “a,” “an”and “the” can include the plural forms as well, unless the contextclearly indicates otherwise. It will be further understood that theterms “comprises” and/or “comprising,” as used herein, can specify thepresence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof.

As used herein, the term “and/or” can include any and all combinationsof one or more of the associated listed items.

As used herein, phrases such as “between X and Y” and “between about Xand Y” can be interpreted to include X and Y.

As used herein, phrases such as “between about X and Y” can mean“between about X and about Y.”

As used herein, phrases such as “from about X to Y” can mean “from aboutX to about Y.”

It will be understood that when an element is referred to as being “on,”“attached” to, “connected” to, “coupled” with, “contacting,” etc.,another element, it can be directly on, attached to, connected to,coupled with or contacting the other element or intervening elements mayalso be present. In contrast, when an element is referred to as being,for example, “directly on,” “directly attached” to, “directly connected”to, “directly coupled” with or “directly contacting” another element,there are no intervening elements present. It will also be appreciatedby those of skill in the art that references to a structure or featurethat is disposed “directly adjacent” another feature may have portionsthat overlap or underlie the adjacent feature, whereas a structure orfeature that is disposed “adjacent” another feature may not haveportions that overlap or underlie the adjacent feature.

Spatially relative terms, such as “under,” “below,” “lower,” “over,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms can encompass different orientations of adevice in use or operation, in addition to the orientation depicted inthe figures. For example, if a device in the figures is inverted,elements described as “under” or “beneath” other elements or featureswould then be oriented “over” the other elements or features.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. Thus, a “first” element discussed below couldalso be termed a “second” element without departing from the teachingsof the present disclosure. The sequence of operations (or steps) is notlimited to the order presented in the claims or figures unlessspecifically indicated otherwise.

As used herein, the terms “modulate” or “modulating” can refer tocausing a change in neuronal activity, chemistry, and/or metabolism. Thechange can refer to an increase, decrease, or even a change in a patternof neuronal activity. The terms may refer to either excitatory orinhibitory stimulation, or a combination thereof, and may be at leastelectrical, magnetic, thermal, ultrasonic, optical or chemical, or acombination of two or more of these. The terms “modulate” or“modulating” can also be used to refer to a masking, altering, oroverriding of neuronal activity.

As used herein, the term “target nerve” can refer to any portion of ahuman (or other mammalian) nervous system that has been identified tobenefit from receiving electric current. Non-limiting examples of targetnerves can include the facial nerve and any one of its branches, such asthe temporal branch, the zygomatic branch, the buccal branch, themarginal mandibular branch, and the cervical branch. Other examples oftarget nerves are illustrated in FIG. 8 and described in more detailbelow.

As used herein, the term “substantially ablate” can refer to damagecaused to a target nerve that results in partial or complete nervoustissue or nerve cell necrosis. The term can also refer to nervous tissueor nerve cell damage that falls short of complete ablation, e.g., somelevel of agitation or damage that is imparted to the nervous tissue ornerve cell to inure a desired change in the cellular makeup and/orelectrical activity of the tissue/cell, rather than necrosis of thetissue/cell.

As used herein, the term “subject” can refer to any warm-bloodedorganism including, but not limited to, human beings, pigs, rats, mice,dogs, goats, sheep, horses, monkeys, apes, rabbits, cattle, etc.

As used herein, the terms “substantially blocked” or “substantiallyblock” when used with reference to activity at or associated with atarget nerve target can refer to a complete (e.g., 100%) or partialinhibition (e.g., less than 100%, such as about 90%, about 80%, about70%, about 60%, or less than about 50%) of nerve conduction through thetarget nerve.

As used herein, the term “activity” when used with reference to a targetnerve can, in some instances, refer to the ability of a target nerve toconduct, propagate, and/or generate an action potential. In otherinstances, the term can refer to the frequency at which a target nerveis conducting, propagating, and/or generating one or more actionpotentials at a given moment in time. In further instances, the term canrefer to the frequency at which a target nerve is conducting,propagating, and/or generating one or more action potentials over agiven period of time (e.g., seconds, minutes, hours, days, etc.).

As used herein, the term “electrical communication” can refer to theability of an electric field generated by an electrode or electrodearray to be transferred, or to have a neuromodulatory effect, withinand/or on a target nerve.

As used herein, the terms “treat” or “treating” can refer totherapeutically regulating, preventing, improving, alleviating thesymptoms of, and/or reducing the effects of a neuromuscular defect. Assuch, treatment also includes situations where a neuromuscular defect,or at least symptoms associated therewith, is completely inhibited,e.g., prevented from happening or stopped (e.g., terminated) such thatthe subject no longer suffers from the neuromuscular defect, or at leastthe symptoms that characterize the neuromuscular defect.

As used herein, the terms “neuromuscular defect” or “neuromuscularjunction disorder” can refer to abnormal or dysfunctional communicationbetween a nerve and a muscle.

Overview

The present disclosure relates generally to an apparatus and method forneuromodulation, and more particularly to an apparatus and method forinterrupting nerve conduction through a target nerve to treat aneuromuscular defect. Conventional nerve ablation procedures, such asthose used to ablate peripheral nerves using RF energy, can be effectivein inhibiting unwanted muscle contraction and movement. Due to therelatively shallow anatomical location of such nerves, however, deliveryof ablation energy often causes undesirable damage to tissuessurrounding the ablated nerve(s). Advantageously, the present disclosureprovides apparatus and methods for protecting superficial tissue planesfrom inadvertent heat damage during nerve ablation procedures, therebyreducing or preventing unwanted scarring and disruption of neighboringnerves and/or blood vessels. As described in more detail below, thepresent disclosure can be used to treat a variety of neuromusculardefects and/or neuromuscular junction disorders, such as cosmeticconditions affecting the face and neck, as well as headaches andneuromuscular pain.

Apparatus

One aspect of the present disclosure includes a treatment probe 10(FIG. 1) comprising an elongated body member 12 and a needle portion 14.The elongated body member 12 can include an ergonomically-shaped housinghaving a proximal end portion 16, a distal end portion 18, and anintermediate portion 20 extending between the proximal and distal endportions. The elongated body member 12 can have a tubular or cylindricalshape; however, it will be appreciated that other ergonomic shapes arepossible. In some instances, each of the proximal and distal endportions 16 and 18 can have a tapered configuration (relative to theintermediate portion 20) to assist with handling the treatment probe 10.Although not shown in FIG. 1, the elongated body member 12 can includean internal reservoir for holding a tumescent fluid. Alternatively, theelongated body member 12 can include one or more external fluid lines(not shown) connected to a source of tumescent fluid (not shown). All oronly a portion of the elongated body member 12 can be made of a durablematerial, such as a metal, metal alloy, or a hardened plastic.

In another aspect, a power button 22 can be operably disposed on theelongated body member 12. Although the power button 22 is shown in FIG.1 as being disposed on the intermediate portion 20 of the body member12, it will be appreciated that the power button can be disposed aboutany other portion of the elongated body member to facilitate use of thetreatment probe 10. As described in more detail below, the power button22 can be used to control one or a combination of functions of thetreatment probe 10, such as delivery of electrical energy, flow of atumescent fluid, aspiration and/or suctioning, and electrical sensing.

Although not shown, a power source can also be associated with theelongated body member 12. The power source can comprise any devicecapable of generating electrical energy, such as high frequencyultrasound, high energy radiowaves, high frequency electricalstimulation, and laser energy. In some instances, the power source caninclude a battery housed within the elongated body member 12. In otherinstances, the power source can be externally coupled to the elongatedbody member 12. For example, the power source can be electricallyconnected to the proximal end portion 16 of the elongated body member 12using an insulated electrical lead or wire (not shown).

In another aspect, the distal end portion 18 of the elongated bodymember 12 can be connected (e.g., directly connected) to the needleportion 14. The needle portion 14 can generally comprise a hollowconduit that is shaped and configured to penetrate tissue, such as skin.In some instances, all or only a portion of the needle portion 14 can becomprised of a non-conductive material, such as a hardened plastic. Inother instances, the needle portion 14 can be comprised of a metal ormetal alloy, such as stainless steel. As shown in FIGS. 2A-B, the needleportion 14 can include an elongated shaft having oppositely disposeddistal and proximal ends 24 and 26. The needle portion 14 can alsoinclude a channel 28 or lumen, which is defined by an outer surface 30and an inner surface 32 of the shaft. The channel 28 or lumen can beconfigured to receive a tumescent fluid. In some instances, the channel28 or lumen can be in fluid communication with a tumescent fluidreservoir housed within the elongated body member 12. Alternatively, thechannel 28 or lumen can be in fluid communication with a fluid line (notshown) that extends through the elongated body member 12 to an externaltumescent fluid reservoir.

The needle portion 14 includes a length L, which extends between thedistal and proximal ends 24 and 26 of the shaft. The length L of theneedle portion 14 can be between about 0.5 cm to about 5 cm, or more,depending upon the intended application of the treatment probe 10. Insome instances, the proximal end 26 of the shaft can be directlyconnected to the proximal end portion 16 of the elongated body member12. In other instances, the distal end 24 of the shaft can have atapered and/or sharpened configuration (e.g., a sharpened tip) tofacilitate insertion of the needle portion 14 into a subject. Althoughthe shaft is shown as extending axially from the proximal end portion 16of the elongated body member 12, it will be appreciated that a portionof the shaft (e.g., the distal end 24) may be curved or have an arcuateconfiguration. The shaft of the needle portion 14 can also include anouter diameter, which corresponds to a conventional needle gauge. Thus,in some instances, the needle portion 14 can comprise a needle (e.g., ahypodermic needle) having a gauge between 7 and 34.

In another aspect, the needle portion 14 includes at least one electrode34 and at least one fluid port 36, which are configured to deliverelectrical energy and a tumescent fluid, respectively, so thatsuperficial tissue planes overlying a target nerve are protected frominadvertent heat damage as a result of application of electrical energyto a target nerve. As shown in FIGS. 2A-B, the fluid ports 36 and theelectrode 34 are oppositely disposed from one another. The electrode 34and the fluid ports 36 can be oppositely disposed from one another otherby an angle A sufficient to ensure that electrical energy is deliveredto a target nerve but not to superficial tissue planes overlying thetarget nerve. Thus, in some instances, the angle A can range from about180° to about 90°. A variety of fluid port 36 and electrode 34configurations are possible, so long as superficial tissue planesoverlying a target nerve are protected from inadvertent heat damage as aresult of application of electrical energy to a target nerve. As shownin FIGS. 3A-B, for example, the fluid ports 36 can be axially offsetfrom, and radially aligned with, the electrode 34. In another example,the fluid ports 36 can be axially and radially offset from the electrode34 (FIGS. 4-5).

Each of the fluid ports 36 extends between the outer and inner surfaces30 and 32 of the shaft, and includes an opening 38 in fluidcommunication with the channel 28 or lumen. Although three fluid ports36 are shown in FIGS. 2A-B, it will be appreciated that the needleportion 14 can include one, two, four, or more fluid ports. The fluidports 36 can have any desired cross-sectional shape, such as ovoid,circular, square, rectangular, etc. Each of the fluid ports 36 can havethe same or different cross-sectional shape. The diameter of each fluidport 36 can be the same or different as compared to the diameter(s) ofother fluid port(s). The fluid ports 36 can be equally or asymmetricallyspaced apart from one another.

One or more electrodes 34 can be oppositely disposed from the fluidports 36 such that electrical energy delivered by the electrode(s) isdirected away from the flow of tumescent fluid through the fluid ports.The electrode(s) 34 can comprise any one or combination of materialscapable of conducting electrical energy, such as platinum,platinum-iridium, stainless steel, gold-plated copper, and the like.Additionally or optionally, at least a portion of each electrode 34 canbe embedded within, or coated with, a polymeric material (or othersimilar material) (e.g., silicone) to protect tissue from abrasion,promote biocompatibility and/or electrical conduction. The electrode(s)34 can have any desired shape, such as square, ovoid, circular,rectangular, etc. The electrode(s) 34 can have the same shape or,alternatively, each of the electrodes can have a different shape. Theelectrode(s) 34 can be equally or asymmetrically spaced apart from oneanother.

In another aspect, the needle portion 14 can include at least onesensing electrode 40 for monitoring or detecting the electrical activityof a target nerve. Similar to the electrode 34, the sensing electrode 40can be located opposite the fluid ports 36. As shown in FIGS. 2A-B, forexample, the sensing electrode 40 can be located proximal to theelectrode 34; although, it will be appreciated that the sensingelectrode can be located distal to the electrode. The sensing electrode40 is capable of monitoring a desired metabolic parameter (e.g.,electrical activity) associated with a nerve, nervous tissue, and/ormuscle function. For example, the sensing electrode 40 can include atleast one electromyographic (EMG) electrode capable of receiving asignal from a target nerve or muscle tissue when the sensing electrodeis placed in electrical contact with the target nerve or muscle tissue.As explained in more detail below, the sensing electrode 40 can be usedto verify that a target nerve is an appropriate target for ablation.

In another aspect, the treatment probe can include a tumescent fluiddelivery and/or aspiration mechanism (not shown in detail). In someinstances, a tumescent fluid delivery and/or aspiration mechanism caninclude one or more pumps (not shown) in fluid communication with thechannel 28 or lumen of the needle portion 14. For example, the treatmentprobe 10 can include a pump configured to deliver tumescent fluidthrough the channel 28 or lumen. Alternatively or additionally, thetreatment probe 10 can include the same or a different pump forsuctioning fluid (e.g., blood, tumescent fluid, etc.) from the areasurrounding a target nerve. In some instances, a pump (or pumps) can bedisposed within the elongated body member 12 or, alternatively, a pump(or pumps) can be located externally from the treatment probe 10.Operation of the fluid delivery and/or aspiration mechanism can becontrolled by the power button 22.

Methods

Another aspect of the present disclosure can include a method 50 (FIG.6) for treating a neuromuscular defect or neuromuscular junctiondisorder in a subject. At Step 52, the method 50 can include identifyinga neuromuscular defect in the subject. Generally, the neuromusculardefect can include any disease, disorder, or condition that adverselyaffects both nervous elements (e.g., brain, spinal cord, peripheralnerve) and muscle (e.g., striated or smooth). Non-limiting examples ofneuromuscular defects can include cosmetic defects, neurologicalmovement disorders, neuromuscular pain, and headaches.

Non-limiting examples of cosmetic defects can include frown lines, linesor wrinkles between the eyes 66 (FIG. 7), crow's feet, horizontal linesin the forehead and neck, wrinkles around the mouth and chin, skinfurrows, contractions in the face and neck, spasms in the face or neck,and neck bands.

Neurological movement disorders can include any neurological disease orcondition that affects the speed, fluency, quality, and/or ease ofmovement in a subject. For example, abnormal fluency or speed ofmovement (dyskinesia) may involve excessive or involuntary movement(hyperkinesia) or slowed or absent voluntary movement (hypokinesia).Examples of neurological movement disorders can include, but are notlimited to, dystonias, torticollis, bleharospasm, and uncontrolledgrimacing.

Non-limiting examples of neuromuscular pain can include myofascial pain,fibromyalgia, TMJ pain, carpal tunnel syndrome, pain associated withmuscular dystrophy, orofacial pain, chronic head and neck pain, and painassociated with herniated and/or bulging or ruptured vertebral discs.Myofascial pain can involve any one or combination of nerves that supplythe face or, alternatively, indirect (referred) pain from otherstructures in the head, e.g., blood vessels. Myofascial pain may berelated to headache (e.g., migraine), muscular syndromes, such as TMJ,and herpetic or rheumatic disease or injury.

Non-limiting examples of headaches can include migraines, tensionheadaches, cluster headaches, trigeminal neuralgia, secondary headaches,and miscellaneous-type headaches. Migraines can include intense anddisabling episodic headaches typically characterized by severe pain inone or both sides of the head. For example, migraines can includemigraine without aura, migraine with aura, and migraine with aura butwithout headache. Cluster headaches can include extremely painful anddebilitating headaches that occur in groups or clusters. For example,cluster headaches can include cluster-type headaches, histamineheadaches, histamine cephalalgia, Raedar's syndrome, and sphenopalatineneuralgia.

To identify the neuromuscular defect, a subject is monitored for one ormore observable clinical symptoms associated with a particularneuromuscular defect. As shown in FIG. 7, for example, a subjectsuffering from blepharospasm may exhibit involuntary and sustainedmuscle contractions of the muscles around the eyes 66. Alternatively,symptoms associated with a particular neuromuscular defect may not beclinically observable. In this case, the subject may be asked to reporthis or her symptom(s) associated with the particular neuromusculardefect. For example, the subject may report the sensation of facial orhead pain associated with a headache.

After the neuromuscular defect has been identified, a target nerve canbe located at Step 54. Generally, the target nerve can include anyportion of a subject's nervous system that has been identified tobenefit from receiving electric current based on the identifiedneuromuscular defect. Examples of target nerves in the face of asubject, as well as the muscles innervated by the target nerves areillustrated in FIG. 8. It should be appreciated, however, that othertarget nerves, such as those of the peripheral nervous system may alsobe targeted by the method 50.

Referring to FIG. 8, the facial nerve 68 is the motor nerve thatcontrols a significant portion of the muscles responsible for facialexpressions. The branches of the facial nerve 68 pass around and throughsuperficial facial and neck muscles to control the corrugator superciliimuscle 70, the procerus muscle 72, and the platysma myoides muscle 74,among many others. The facial nerve 68 is the seventh cranial nerve,which is part of the peripheral nervous system of the body. Disorders ordefects in facial nerve 68 function can cause various cosmetic defects,such as blepharospasm. Thus, the facial nerve 68 and/or one of itsbranches can be an appropriate target nerve for treating a subjectsuffering from blepharospasm.

The corrugator supercilii 70 is a small and narrow pyramidal muscle. Thecorrugator supercilii 70 is located at the inner extremity of theeyebrow beneath the orbicularis palpebrarum muscle 76. As FIG. 8 shows,the temporal branch 78 of the facial nerve 68 provides additional nervebranches 80 to the corrugator supercilii muscle 70. The corrugatorsupercilii muscle 70 is called the “frowning muscle” because it drawsthe eyebrows downward and inward, producing vertical wrinkles in theforehead and in the space between the eyebrows.

The procerus 72 is a small, pyramidal band of muscles located over thenasal bone between the eyebrows. The zygomatico-buccal branch (not shownin detail) of the facial nerve 68 supplies the procerus muscle 72. Theprocerus muscle 72 draws down the inner angle of the eyebrows andproduces transverse wrinkles over the bridge of the nose.

The platysma myoides 74 is a broad, thin plane of muscular fiberslocated immediately beneath the superficial fascia on each side of theneck. The cervical branch (not shown in detail) of the facial nerve 68supplies the platysma myoides muscle 74. The platysma myoides muscle 74produces a wrinkling of the surface of the skin of the neck, in anoblique direction, when the entire muscle is brought into action. Italso serves to draw down the lower lip and angle of the mouth on eachside.

A neuromuscular defect can lead to uncontrolled contraction of one ormore of the corrugator supercilii 70, the procerus 72, and the platysmamyoides 74 muscles. Uncontrolled contraction of the corrugatorsupercilii muscle 70 or the procerus muscle 72, for example, cancontinuously contract the brow, giving the outward appearance ofdispleasure or disapproval even in the absence of the correspondingemotional state. Likewise, uncontrolled contraction of the platysmamyoides muscle 74 (called torticollis) can lead to sudden neck movement.Repeated normal contraction of the platysma myoides muscles 74 can alsolead to the formation of aesthetically displeasing bands in the skinarea below the neck over time. Even without hyperfunctional dysfunction,normal contraction of these muscles can, over time, cause aestheticallydispleasing frown lines or furrows in the forehead or in the spacebetween the eyebrows. Additionally, exposure to the sun can acceleratethis wrinkling process.

At Step 56, a treatment probe 10 can be positioned about a target nerve.Any one or combination of approaches can be used to access the targetnerve with the treatment probe 10. For example, the needle portion 14 ofthe treatment probe 10 can be inserted directly through the skinadjacent a target nerve or, alternatively, an incision 82 (FIG. 9) canbe made in the skin adjacent the target nerve. The needle portion 14 canbe positioned so that at least one electrode 34 and/or at least onesensing electrode 40 is/are in electrical communication with the targetnerve. For example, the needle portion 14 can be oriented so that atleast one electrode 34 is directly adjacent the target nerve. In otherinstances, the needle portion 14 of the treatment probe 10 is urgedthrough the incision 82 so that the distal end 24 of the needle portion,and in particular the electrode 34, is in electrical contact with thetarget nerve. By “electrical contact” it is meant that when electriccurrent is delivered to the electrode 34, deplorization of at least oneneuron comprising the target nerve is elicited.

In a subject suffering from blepharospasm, for example, an incision 82can be made near the right corner of a subject's eye 66 using a scalpel(not shown). In this case, the incision 82 should be made so that aportion of the facial nerve 68 and/or one of its branches issufficiently exposed to facilitate accurate placement of the treatmentprobe 10. As shown in FIG. 9, for example, the needle portion 14 of thetreatment probe 10 can be inserted into the incision 82 so that theelectrode 34 is adjacent a portion of the facial nerve 68 and/or one ofits branches. As discussed in more detail below, the position of theelectrode 34 relative to the target nerve can be adjusted using thesensing electrode 40 during placement of the treatment probe 10. Forexample, the position of the electrode 34 can be adjusted based onsensed electrical patterns in the target nerve and/or tissue surroundingthe target nerve using EMG mapping.

Following placement of the needle portion 14, a determination is made asto whether the target nerve is appropriate for ablation at Step 58. Toverify whether the target nerve is appropriate for ablation, electriccurrent is delivered to the electrode 34. Electric current can bedelivered to the electrode 34 continuously, periodically, episodically,or a combination thereof. For example, electric current can be deliveredin a unipolar, bipolar, and/or multipolar sequence or, alternatively,via a sequential wave, charge-balanced biphasic square wave, sine wave,or any combination thereof. Electric current can be delivered all atonce or, where the needle portion 14 includes two or more electrodes 34,electric current can be delivered to only one of the electrodes using acontroller (not shown) and/or known complex practice, such as currentsteering.

The particular voltage, current, and frequency delivered to theelectrode 34 may be varied as needed. For example, electric current canbe delivered to the electrode 34 at a constant voltage (e.g., at about0.1 v to about 25 v), at a constant current (e.g., at about 25microampes to about 50 milliamps), at a constant frequency (e.g., atabout 5 Hz to about 10,000 Hz), and at a constant pulse-width (e.g., atabout 50 μsec to about 10,000 μsec).

Delivery of electric current to the electrode 34 stimulates the targetnerve, i.e., causes the target nerve to increase the frequency of nerveimpulses. Depending upon the anatomical structure(s) and/or other nervepathways innervated by the target nerve, a measurable result indicativeof the appropriate target nerve can be determined by the sensingelectrode 40 upon delivery of electric current. In a subject sufferingfrom headache, for example, the measurable result may include somedegree of pain relief. Alternatively, in a subject suffering fromblepharospasm, the measurable result may include a reduction inuncontrolled blinking. If an appropriate measurable result is notobserved upon delivery of electric current, the needle portion 14 can bere-positioned, electric current again delivered to the electrode 34, anda measurable result then observed.

At Step 60, an appropriate volume of a tumescent fluid can be injectedinto the tissue surrounding the target nerve (FIG. 10). For example, thetumescent fluid can be delivered to the tissue surrounding the targetnerve by flowing the tumescent fluid through the fluid ports 36 so thatthe flow of tumescent fluid is directed away from the target nerve. Thetumescent fluid can be stored in the treatment probe 10 or,alternatively, supplied from an external fluid source (not shown). Thetumescent fluid can comprise any solution capable of protectingsuperficial tissue planes from inadvertent heat damage and enhancingelectro-mechanical condition during delivery of electric current to thetarget nerve. For example, the tumescent fluid can comprise sterilewater or an electrolyte solution (e.g., a physiologically normal salinesolution).

Depending upon the particular neuromuscular defect being treated, thetumescent fluid can also include at least one pharmacological agent.Non-limiting examples of pharmacological agents can include anestheticagents, such as lidocaine, marcaine, nesacaine, diprivan, novocaine,ketalar and xylocaine, vasoconstrictive agents, such as epinephrine,levarterenol, phenylephrine, athyladrianol and ephedrine,anti-inflammatory agents, such as free radical scavengers andanti-oxidants (e.g., superoxide dismutase, catalase, nitric oxide,mannitol, allopurinol, and dimethyl sulfoxide), NSAIDS (e.g., aspirin,acetaminophen, indomethacin and ibuprofen), steroidal agents (e.g.,glucocorticoids and hormes), calcium channel blockers (e.g., nimodipine,nifedipine, verapamil and nicardipine), NMDA antagonists (e.g.,magnesium sulfate and dextromethorphan), and neurotoxic agents, such asBotulinum toxin.

After an appropriate volume of tumescent fluid has been injected intothe tissue surrounding the target nerve, the target nerve can besubstantially ablated at Step 62. To substantially ablate the targetnerve, the electrode 34 can be positioned adjacent or directly adjacenta portion of the contractile chain comprising the target nerve. Thecontractile chain comprises nerve tissue (e.g., a neuron), aneuromuscular junction 84 (FIG. 11A) (which generally forms theinterface between nerves and muscles), muscle tissue, and connectivetissue. As shown in FIG. 11A, for example, the electrode 34 can bepositioned substantially adjacent a neuromuscular junction 84. Although,it will be appreciated that the electrode 34 can be positioned directlyadjacent a neuromuscular junction 84.

Muscular movement is generally controlled by stimulation of a nerve. Themotor unit of the neuromuscular system contains three components: motorneuron (spine), axon (spine to motor endplate), and innervated musclefibers (endplate to muscle). Each muscle receives one or more supplynerves, and the supply nerve generally enters deep into the musclesurface near its origin where the muscle is relatively immobile. Oftentimes, blood vessels can accompany the nerve to enter the muscle at theneurovascular hilum. Each nerve contains motor and sensory fibers, motorendplates, vascular smooth muscle cells, and various sensory endings andendings in fascia. When the nerve enters the muscle, it breaks off intoa plexus running into the various layers of muscle epimysium, perimysiumand endomysium, each terminating in several branches joining a musclefiber at the motor endplate.

Substantially ablating one or more of these tissues may be sufficient totemporarily or permanently inhibit (or substantially block) musclecontraction. Substantially ablating a target nerve may interrupt ordisable nerve impulses by disrupting conductivity, and thereby blockingor substantially blocking nerve activity. Disruptions in nerveconductivity may be caused by eliminating or decreasing chargedifferences across plasma membranes, either mechanically or chemically,destroying Schwann cells that insulate the axonal processes, repeatedinjury/healing cycles timed to limited capacity for neuron regeneration,or a combination thereof.

The electrode 34 can be brought into direct or indirect contact with thetarget nerve. By “direct” it is meant that the electrode 34 is broughtinto physical contact with the target nerve. By “indirect” it is meantthat the electrode 34 is positioned about the target nerve withoutdirectly contacting the target nerve, such that delivery of electriccurrent to the electrode can modulate activity of the target nerve.Regardless of the specific component of the contractile chain which issubstantially ablated, delivery of electric current to the target nervecan inhibit contraction of a muscle that would otherwise form or causethe neuromuscular defect.

Substantial ablation of the target nerve is accomplished when electriccurrent is delivered to the electrode 34 via the power source. Theparameters for delivery of electric current to the electrode 34 can beidentical or similar to the parameters described above. For example,electric current can be delivered to the electrode 34 at a constantvoltage (e.g., at about 0.1 v to about 25 v), at a constant current(e.g., at about 25 microampes to about 50 milliamps), at a constantfrequency (e.g., at about 5 Hz to about 10,000 Hz), and at a constantpulse-width (e.g., at about 50 μsec to about 10,000 μsec).

As shown in FIG. 11B, delivery of electric current to the electrode 34can substantially ablate a neuromuscular junction 84 comprising an endof a facial nerve 68 (or branch thereof) and the orbicularis palpebrarummuscle 76, for example. Such ablation may result in a short-term,long-term, or permanent inactivation of the muscle. Other long-lastingor permanent treatments may involve inducing apoptosis to remodel thetissue behavior with long-term changes in the cellular life and/orproliferation cycles.

Specific ablative approaches used to change the function of a targetnerve and its corresponding muscle(s) in a desired way, or for a desiredtime, may be induced by appropriate delivery of electric current to theelectrode 34. Alternative ablative approaches that may be shorter ineffect can include, for example, stunning of one or more components ofcontractile chain or inactivating one or more of the components.Ablative approaches that effectively block the release of, or responseto, chemicals (e.g., neurotransmitters) along the contractile chain mayalso be sufficient to inhibit (e.g., temporarily or permanently)muscular contraction in response to signals transmitted along the neuralpathways.

After substantially ablating the target nerve, the subject can bere-assessed to determine if the method 50 was effective in treating theneuromuscular defect. In a subject suffering from blepharospasm, forexample, a medical practitioner or other health care professional canobserve the subject for uncontrolled blinking. Depending upon theobserved result, the method 50 can be repeated at Step 64. If thesubject exhibits normal blinking (FIG. 12), for example, no additionaltreatment may be needed. Where no additional treatment is needed, theincision 82 or entry point used to access the target nerve can besutured or bandaged and the method 50 completed.

Although not illustrated in FIGS. 6-12, it should be appreciated thatthe method 50 can be targeted to any one or combination of the nerves ormuscles identified in FIG. 8 to treat a variety of cosmetic defectsother than blepharospasm. For example, the method 50 may be directedtowards one or more of the levator palpebrae superioris, the frontalis,the levator labii, the corrugator supercilii 70, the zygomaticus minor,the zygomaticus major, the buccinator, and/or the temporalis. Treatmentstargeting contraction of the oticularis may help decrease crow's feetwrinkles, while treatments altering the function of the frontalis mayalleviate wrinkles. Additionally, wrinkles of the chin may be mitigatedby treatment of the mentali, and neck wrinkles may be improved bytreatment of the platysma 74.

Other examples of muscles whose innervating nerve(s) may besubstantially ablated to alleviate a cosmetic defect (or defects) caninclude the glabellar and procerus complex, the nasalis, the depressoranguli oris, the quadratus labii superioris and inferioris, thezygomaticus, the maxillae, the frontalis pars medialis, the frontalispars lateralis, the levator palpebrae superioris, the orbicularis oculipars orbitalis, the orbicularis oculi pars palpebralis, the levatorlabii superioris alaquae nasi, the levator labii superioris, thezygomaticus minor, the zygomaticus major, the levator anguli oris(a.k.a. caninus), the depressor anguli oris (a.k.a. triangularis), thedepressor labii inferioris, the mentalis, the incisivii labiisuperioris, the incisivii labii inferioris, the risorius, the masseter,the internal pterygoid, the digastric, the maxillae, and the quadratuslabii superioris and inferioris. Contraction of these and/or othermuscles may be inhibited by targeting associated nervous tissue(s),connective tissue(s), nerve/muscle interface(s), blood supply, or acombination thereof.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes, and modifications are within the skill of the artand are intended to be covered by the appended claims.

The following is claimed:
 1. A method for treating a neurologicalmovement disorder in a subject, said method comprising the steps of:providing a treatment probe, the treatment probe comprising an elongatedbody member including a proximal end portion, a distal end portion, anda needle portion connected to the distal end portion, the needle portionincluding at least one electrode and at least one fluid port that isoppositely disposed from the at least one electrode, the at least oneelectrode and said at least one fluid port being configured to deliverelectrical energy and a tumescent fluid, respectively, so that theelectrical energy is delivered to a target nerve, but not to superficialtissue planes overlying the target nerve, and superficial tissue planesoverlying the target nerve are protected from inadvertent heat damage asa result of application of electrical energy to the target nerve, the atleast one electrode being disposed on an outer surface of the needleportion and located opposite the at least one fluid port; positioningthe needle portion about a target nerve in a head or neck of thesubject; injecting a tumescent fluid into the tissue surrounding thetarget nerve via the at least one fluid port; and delivering an electriccurrent to the at least one electrode to substantially ablate the targetnerve; wherein the neurological movement disorder is selected from thegroup consisting of torticollis, blepharospasm, and uncontrolledgrimacing.
 2. The method of claim 1, wherein said step of positioningthe needle portion further comprises orienting the at least oneelectrode so that a surface thereof is directly adjacent the targetnerve.
 3. The method of claim 1, wherein said step of injecting atumescent fluid into the tissue surrounding the target nerve furtherincludes injecting a pharmacological agent into the tissue surroundingthe target nerve.
 4. The method of claim 3, wherein the pharmacologicalagent is selected from the group consisting of an anesthetic agent, ananti-inflammatory agent, an electrolyte solution, and a neurotoxicagent.
 5. The method of claim 4, wherein the neurotoxic agent comprisesBotulinum toxin.
 6. The method of claim 1, wherein said step ofinjecting a tumescent fluid into the tissue surrounding the target nerveprotects superficial tissue planes from inadvertent heat damage andenhances electro-mechanical conduction during delivery of electriccurrent to the target nerve.
 7. The method of claim 1, wherein said stepof injecting a tumescent fluid into the tissue surrounding the targetnerve anesthetizes at least a portion of the tissue.
 8. The method ofclaim 1, wherein at least one of high frequency electrical stimulation,or laser enemy is delivered to the target nerve.